Device for insertion into keyholes for obstructing same to prevent unauthorized entry



Aug. 21, 1945. o. J. LOFQWIST 2,383,397

v 'DEVICE FOR INSERTION INTO KEYHOLES FOR OBSTRUCTING SAME "1'0 PREVENT UNAUT IZED ENTRY Filed Sept. 1943 M/VE/VTQIQZ 0. .1 Lmgmsr Patented Aug. 21, 1945 DEVICE FOR INSERTION INTO KEYHOLES FOR OBSTRUCTING SAME TO PREVENT UNAUTHORIZED ENTRY Olof Jonsson Lofqwist, London, England Application September 1, 1943, Serial No. 500,832 In Great Britain September 15, 1942 1 Claim.

This invention relates to a device for insertion into keyholes for obstructing same so as to prevent entry by an unauthorized person in possession of a suitable key. In particular the device of this invention is intended for insertion into keyh'oles of mortise and similar lock in which the keyhole extends through the lock from one side to the other. 'The invention is not applicable to tumbler or barrel looks.

The object of the invention is to provide a device for obstructing a keyhole which is capable of being conditioned in a keyhole by an authorized person and which cannot, without force, be removed by an unauthorized person to gain access to the keyhole.

Broadly, according to the present invention a device for insertion into keyholes oi" mortise and similar locks for obstructing same for the purpose specified, comprises a pair of blade-like members which are relatively displaceable, said blades when closed (that is, not displaced) being capable of insertion into and through a keyhole to the other side and then being relatively displaced or openedand being capable of engaging by their inner ends the other side of the lock remote from that intended to receive a key so as to prevent withdrawal of the device from the lock. The other or outer ends of the blades are so constructed that the bladescan be locked together to hold the blades in an open position until unlocked. 1 I

According to one form of the invention, the blade are pivoted together scissor fashion and the outer ends of the blades are widened and each outer end is formed unth holes. By opening the blades different holes in the respective outer ends of the blades are brought into alignment through which the locking staple of a padlock or other suitable means can be inserted to maintain the blades in an open position with their inner ends engag ing the other side of the lock.

In order that the invention may be clearly understood and readily carried into effect, reference will now be made to the accompanying sheet of drawings which illustrate one form of the invention by way of example. In the drawing:

Figure 1 is a side view showing the blades of the device closed,

Figure 2 is a side view, which for the sake of clarity shows the blades opened beyond their normal position, and

Figure 3 is a view showing the device in use.

Referring to the drawing, the device comprises a pair of blade-like members I and 2 pivoted together at 3 scissor fashion, said blades I and 2 when closed being capable of insertion through a keyhole (indicated diagrammatically at 4 in Figure 3) to the other side, and then opened out so that their inner ends la and 2a are splayed. The blade-like members are adapted at their outer ends indicated at lb and 2b to receive means for preventing closing of the blades after they have been opened out to prevent withdrawal thereof by an unauthorized person.

By inner ends, as used herein and in the accompanying claim, is meant the ends or the blades which are directed away from the user and normally directed towards the inside of the door, while by outer ends is meant the ends normally outermost of the door and accessible to the user. The device can, of course, be inserted from either side of a door or the like.

The adaptation of the outer ends lb and 2b of the blade-like members I and 2 consists in widening the blades at these ends and forming three or any suitable number of holes 5 in each blade, the holes 5 of both blades registering when the blades are closed as shown by Figure 1. After the blades l and 2 have been inserted into a keyhole and opened out, the locking staple of a padlock o other suitable means 6 is inserted through a pair of aligned openings 5, it being understood that the openings of one blade are made to align with different openings 5 in the other blade when the blades are opened.

Thus until the padlock 6 is removed it is impossible to close the-blades I and 2 as the locking staple of the padlock passing through the holes 5 will prevent movement of the blades It is preferred to flare the inner ends la and lb of the blades so that the effective degree of opening of the blades is increased To allow for a finer degree of opening of the blades l and 2, additional holes I and B may be formed. respectively in the two. :blades. The hole I in the blade I is formed centrally beneath the center one of the three holes 5 of that blade while the hole 8 in the other blade is formed below but between the centre and an end hole 5 of the blade 2. By bringing the holes I and 8 into registration a half-setting may be obtained. Where more than three holes 5 are formed in each blade then two or more additional holes 8 may be formed in the blade 2 with the selected one of which the hole 1 may be made to register.

I claim:

Adevice for insertion into the keyhole or a lock to prevent the insertion'of a key therein comprising a pair of superimposed identically-shaped flat plates pivoted together intermediate their ends for swinging movement between a. closed position in which they register with one another and are bounded by a common perimeter for insertion of corresponding end portions thereof into a keyhole and. an open position in which they extend in crossed relationship to each other and their said 'correspondingend portions thereby are prevented from "being withdrawn from the "key 

